that day when we finally got to the river,we found the boat-----------to the bottom of it.
问题描述：
that day when we finally got to the river,we found the boat-----------to the bottom of it.
A,sank B,was sinking C,has sunk D,had sunk
答
大意：我们终于去了这条河的这天,我们发现了这条船,……沉在河底
这里是过去完成时态,过去去河边的时候,已经发现沉在河底了
所以选择 D,had sunk那像这道题，When i passed by his seat，i found he--------to pick up something on the ground.为什么填was bending呢